Tom Gjelten

Fifteen years after the attacks of Sept. 11, Americans have grown aware not only of the danger of terrorism but also of the reality that their nation is far less white, Christian and European than it used to be.

"Culturally, we're a country of Bollywood and bhangra and tai chi and yoga and salsa and burritos and halal and kosher," says Diana Eck, professor of comparative religion at Harvard University and author of A New Religious America.

(Editor's note: Both major presidential candidates this year are Protestants. Both of their running mates were raised as Catholics. Beyond that, their faith profiles are very different. We dug into the faiths of the Republican candidates below and of the Democratic ticket here.)

(Editor's note: Both major presidential candidates this year are Protestants. Both of their running mates were raised as Catholics. Beyond that, their faith profiles are very different. We dug into the faiths of the Democratic candidates below and of the Republican ticket here.)

A newspaper correspondent observing Abraham Lincoln's second inauguration in March 1865 — delivered to a crowd "as far as the eye could reach" — noted that the president laid his right hand on a Bible and, facing Supreme Court Chief Justice Salmon Chase, swore to preserve, protect and defend the U.S. Constitution.

The Jews who immigrated to America in the early 20th century brought with them their history as a persecuted people. Many were fleeing pogroms and anti-Semitic attacks in Europe, and those experiences bonded them to other groups that also faced discrimination.

America's culture war, waged in recent years over gender roles, sexuality and the definition of marriage, is increasingly being fought inside evangelical Christian circles. On one side are the Christians determined to resist trends in secular society that appear to conflict with biblical teaching. On the other side are the evangelicals willing to live with those trends.

For Albert Mohler, president of the Southern Baptist Theological Seminary in Louisville, Ky., the key question is "whether or not there is a binding morality to which everyone is accountable."

The global refugee crisis, political strife and economic dislocation all contributed to a worldwide deterioration of religious freedom in 2015 and an increase in "societal intolerance," according to the U.S. Commission on International Religious Freedom.

"At best, in most of the countries we cover, religious freedom conditions have failed to improve," says Princeton professor Robert George, the USCIRF chairman. "At worst, they've spiraled downward."

Editor's note: Radovan Karadzic was one of the dominant figures of the Bosnian war, serving as president of the "Serb Republic" in Bosnia from 1992 to 1995. The International Criminal Tribunal in The Hague on Thursday found him guilty of multiple crimes, including the slaughter of about 8,000 Muslim men and boys in the town of Srebrenica. NPR's Tom Gjelten covered the war in Bosnia, and Karadzic, for years.

Given all that has happened in the last 20 years, many people will not recall the war in Bosnia. Remind us what happened.

For Muslim-Americans, there was a world before Sept. 11 and the wars in Afghanistan and Iraq, and one after. Now, their community faces the dual threats of extremism and growing atheism.

Young Muslim-Americans are angry and frustrated, but not necessarily for the reasons you might think. While bound by their religion and their community, they have opinions as diverse as their backgrounds.

A long-standing principle of U.S. politics, that voters prefer candidates with strong faith beliefs, has been called into question in the 2016 presidential campaign. Recent opinion surveys suggest that voters don't see either Donald Trump or Bernie Sanders as very religious, but that perception does not seem to be damaging their political prospects.

Two trends are evident from new surveys by the Pew Research Center and the Public Religion Research Institute:

Christian conservatives who are battling for the right to promote their faith in public or official settings see themselves locked in an epic contest with a rival religion. But that rival isn't Islam. It's secularism.

Religion is apparently weakening in America. A new report from the Pew Research Center shows that the percentage of Americans who say they believe in God, pray daily and attend church regularly is declining.

Among the findings:

The share of Americans who say they are "absolutely certain" that God exists has dropped 8 percentage points, from 71 percent to 63 percent, since 2007, when the last comparable study was made.

Fifty years ago, President Lyndon B. Johnson signed a new immigration law that would change the face of the nation. But that dramatic impact, ironically, was in good part the result of a major miscalculation by those who actually wanted to limit the bill's effect.

Pope Francis arrives in Washington, D.C., this afternoon for his first trip to the U.S. Here's a look at some of the key moments to watch during the leader of the Roman Catholic Church's six-day visit.